Intercomparing drifts from RAFOS and profiling floats in the deep western boundary current along the Mid-Atlantic Ridge

Francisco Machín; Uwe Send; Walter Zenk

doi:10.3989/scimar.2006.70n11

Authors

Francisco Machín Departamento de Física, Facultad de Ciencias del Mar, Universidad de Las Palmas de Gran Canaria
Uwe Send Forschungsbereich: Ozeanzirkulation und Klima, Physikalische Ozeanographie II, Leibnitz-Institut für
Walter Zenk Forschungsbereich: Ozeanzirkulation und Klima, Physikalische Ozeanographie II, Leibnitz-Institut für

DOI:

https://doi.org/10.3989/scimar.2006.70n11

Keywords:

cycling float, APEX, RAFOS, Lagrangian, Deep Western Boundary Current (DWBC)

Abstract

The Lagrangian nature of cycling floats is evaluated in the framework defined by the Deep Western Boundary Current of the Mid-Atlantic Ridge. In a statistical approach, speeds and drifts are estimated for an APEX cycling float and compared with the velocities inferred from a park ensemble of four eddy-resolving RAFOS floats. They were deployed at the same location and ballasted for drifting at the same mission depth. Displacement errors induced by geostrophic shear and wind forced currents are analyzed. We observe that the velocity estimated from the RAFOS floats is not statistically different from the velocity estimated from the APEX float. Likewise, the initial separation between the cycling float and a simultaneously deployed RAFOS float has been studied in terms of the turbulent diffusivity. Though the performance of this study in comparable cases without a mean current field may be limited, these oceanic observations support exploiting the Lagrangian nature of the cycling floats.

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